This invention relates generally to cartons having strap handles integrally formed with the cartons, and more particularly to a carton with an integral strap handle formed from a carton wall and having a relatively narrow medial grip portion and a pair of wider portions joined to the opposite ends of the medial grip portion. The invention also relates to an arrangement for reinforcing a strap handle of a carton and further to an arrangement for facilitating inward movement of the opposite end portions of a strap handle when the carton is lifted by the strap handle.
Cartons having integral strap handles are well known in the art. An example of the strap handle carton is disclosed in Canadian Patent No. 1,243,987 in which a carton is illustrated as having a strap handle that is formed primarily from a top wall. The strap handle includes a longitudinally elongated medial grip portion and a pair of wider portions located at opposite ends of the medial grip portion. Each wider portion is defined by a pair of cut lines that diverge from the medial grip portion toward the adjacent end edge of the top wall. To lift the carton, the strap handle is gripped at the medial grip portion and pulled upward, which displaces the handle from a stowed position where the handle lies in the plane of the top wall to a use position where it is arched upwardly from the plane of the top wall. During this displacement, the wider portions of the handle are inwardly moved toward each other while the respective parts of the wider portions near the end edges of the top wall are moved downwardly under the plane of the top wall. Such movements cause the wider portions to be wedged into narrower portions of an opening in the top wall defined by the handle itself. In the wedged condition, the opposite side edges of each wider portion are disposed transversely of the complementary edges of the opening and scraped against the complementary edges. This often results in tear in either or both of the handle strap and the top wall. This problem is even aggravated when the carton is actually carried by the handle.
U.S. Pat. No. 5,738,273 discloses another example of the strap handle carton wherein the top wall comprises a pair of inner and outer panels and the strap handle is formed in part from the inner top panel and in part from opposed inner end flaps that are hingedly connected the end edges of the inner top panel. The inner end flaps are glued to opposed outer end flaps that are hingedly connected to the end edges of the outer top panel. For this purpose, glue is applied typically along the lower edges of the end flaps such that the opposed end portions of the strap handle yet are free of restraint of the outer end flaps. This specific glue location is required in order to allow inward movement of the opposed end portions of the strap handle when the carton is lifted by the handle. If glued to the outer end flaps, the handle end portions would be forcibly peeled from the outer end flaps, which could damage the fibrous structure of the handle ends. Although the glue locations are almost precisely controllable by the use of modern packaging machines, having precautionary measures would always be warranted to prevent undesired rupture of the strap handle.
What is needed, therefore, is a carton having an integral, wide-ended strap handle wherein the interference of the strap handle with the top wall is effectively prevented or at least mitigated during the use of the strap handle. Such a carton should be provided with means for preventing the wider portions from being caught by complementary edges of the opening in the top wall. A carton having handle-reinforcing means that would compensate for a potential peeling damage of the strap handle is also needed. What is further needed is an arrangement wherein inward movement of the handle end portions is facilitated upon lifting of the carton by the strap handle. Such an arrangement should be provided particularly when the handle end portions are reinforced.